A 'weightlifter's belt' for buildings could bring quick quake repair

A "weightlifter's belt" of steel straps around an earthquake-damaged building could serve as a cheap, quick repair of such structures, British engineers say. aThe need for such techniques has been brought out in Haiti, where 145,000 people remain homeless from the January 2010 earthquake, researchers at the University of Sheffield said. The technology, involving wrapping metal straps around each floor of the building and then tensioning them by hand or using compressed air tools, could help reduce delays in getting people back in their homes by quickly making them safe and habitable, they said. It is designed for use on reinforced concrete frame buildings, a common construction technique around the world, including countries like Haiti, they said. "The strapping works very much like a weightlifter's belt, by keeping everything tightly compressed to reduce tension on the concrete columns of the structure," researcher Kypros Pilakoutas said. Concrete works well under compression, but not when under tension, which is why it has to be reinforced for use in construction. When the reinforcement is faulty or damaged, it can be very expensive to repair, the Sheffield researchers said. For a typical small dwelling having 6 columns, the seismic rehabilitation would cost around $325 and could be completed in a few days, rather than the several thousand dollars and months needed with other traditional rehabilitation techniques such as jacketing with steel plates or concrete, they said. "Our method not only makes the building stable again very quickly, but it increases the building's ability to deform without breaking, making it more able to withstand further earthquake movement," Pilakoutas said.